Pre-crash safety (PCS) has been realized which reduces or prevents damage from a collision between an own vehicle and an obstacle (target), such as another vehicle, a pedestrian, or a road structure, which is present ahead of the own vehicle and is detected by a target detection device such as an imaging device or a radar device. According to PCS, time to collision (TTC) which is time until an own vehicle collides with an obstacle is obtained on the basis of a relative distance between the own vehicle and the obstacle and a relative speed or a relative acceleration between the own vehicle and the obstacle. Then, on the basis of the time to collision, a driver of the own vehicle is notified by a notification device that the own vehicle is approaching the obstacle, or a braking device of the own vehicle is activated.
However, in a case where axis deviation occurs in which a mounting angle of the target detection device is inclined, an obstacle which is not actually located ahead of the own vehicle is erroneously determined to be located ahead of the own vehicle. The axis deviation of the target detection device can be caused by vibrations occurring while the own vehicle is traveling, an occurrence of a minor collision with the own vehicle, or the like.
Thus, the axis deviation of the target detection device has been conventionally detected. For example, in a case where a radar device is used as the target detection device, deviation information on deviation of a mounting angle of the radar device in a horizontal direction is acquired on the basis of a movement path of a road-side object which has been detected by the radar device. Then, an axis deviation angle of the radar device is calculated by performing statistical processing of a history of the deviation information on the deviation in the horizontal direction (see Patent Literature 1).